As others have said, you're likely going to get a lot of "Kibler, Kibler, Kibler" in terms of a first kit, and I'm not going to say otherwise.
I'm a lot like you...I've had MLs in the past, but when it came time that I wanted to put one together I had to take stock in a similar way...I don't have a dedicated workspace or much more than basic tools around. I've got a plethora of skills and technical knowledge, but no significant gunsmithing experience.
So, considering my options where I live are pretty much a Traditions Kentucky kit, trying to get an Investarms Gemmer Hawken / Lyman Great Plains kit or going Kibler, I went with the latter (Colonial flinter in .58cal). Quality wise, reputation wise, value wise and overall price wise it was pretty much a no-brainer, especially up here in the Great White North. Kibler uses swamped Green Mountain barrels and does have a smoothbore option on the Colonial (just to confirm it ticks those boxes for you).
I'm pretty much wrapping up the last little bits of my build (and I jumped in and did some minor decorating / personalization) and I'd say it's certainly a good option for a first build. While folks who build MLs from blanks (or even go out and find / mill their own blanks) may disparage them as "Lego kits," there is still some work to do and Jim has left the Colonial as a blank slate so you can go further if you want (i.e. carving / personalizations). They are not overly difficult kits (but neither are the Kentucky or Hawken I mentioned above), but they are good quality and should last...plus they do offer a tempting, easy entrance for folks to "fall down the rabbit hole" and do more in the future.
I hope Jim will forgive me for putting it this way (he does frequent the board), but his kits are gateway drug in the ML building world....so grab one, strap in and be prepared to become addicted